The invention relates to well servicing fluids such as drilling mud, workover fluid, rehabilitation fluid, completion fluid, perforation fluid and the like, and to the on location preparation of thermally stable well servicing fluids, more specifically oil-in-water (O/W) macroemulsions, water-in-oil (W/O) macroemulsions and water-in-oil (W/O) microemulsions.
Various well-related activities such as drilling, completion, perforation, rehabilitation and the like involve the use of well servicing fluids for resolving typical problems related to the well including control of formation pressure, circulation of the cuttings out of the well, lubrication of the well equipment, and the like.
Problems frequently encountered include well servicing fluid stability at high temperatures and in the presence of salt typically encountered in downhole environments, formation damage that can be caused by loss of solids from the fluid into the formation, as well as the high cost and lower efficiency associated with the formation, storage and transport of O/W macroemulsions for drilling and W/O macroemulsions for completion.
The need remains for the efficient on location preparation of thermally stable O/W macroemulsions, W/O macroemulsions and W/O microemulsions that exhibit increased stability at elevated temperatures in the presence of salt and that exhibit a reduced tendency toward formation damage.
It is therefore the primary objective of the present invention to provide for an efficient preparation of O/W macroemulsions, W/O macroemulsions and W/O microemulsions which exhibit stability at high well operating temperatures.
It is a further object of the present invention to provide for an efficient preparation of O/W macroemulsions, W/O macroemulsions and W/O microemulsions which exhibit reduced tendency toward formation damage.
It is a further object of the present invention to provide for an efficient preparation of O/W macroemulsions, W/O macroemulsions and W/O microemulsions which exhibit an increased tolerance to saline environments.
It is a further object of the present invention to provide for an efficient preparation of O/W macroemulsions, W/O macroemulsions and W/O microemulsions by providing for surfactant mixture additives which accomplish the above objects of the present invention in terms of efficient on location preparation, thermal stability, saline tolerance and reduced formation damage.
It is a further object of the present invention to provide for versatile O/W macroemulsions, W/O macroemulsions and W/O microemulsions which may be employed in high-depth wells, such as marine bottom wells to low-depth wells.
It is a further object of the present invention to provide for cost effective O/W macroemulsions, W/O macroemulsions and W/O microemulsions.
Other objects and advantages of the present invention will appear below.